In a bowl, mix together flour, salt, oil, chili flakes and yeast. Knead into a dough by adding water little at a time and as required. Cover with a muslin cloth and set aside for an hour.
For the stuffing - Heat oil in a pan and temper with cumin seeds and asafoetida. Saute for a few seconds. Then add the onion, ginger, garlic and green chilies. Fry till light brown.
Now add the veggies, salt, turmeric powder, chili powder and garam masala powder. Cover and cook on a low flame for 2 minutes.
Add the chicken, cheese and amchur powder. Saute for a minute and switch off the flame. Garnish with coriander leaves and set aside to cool down.
For the calzone - Knead the dough once again and then divide into 4-5 portions. Roll out each into a circle by dusting some flour.
Place a little of the stuffing and fold it over like a half moon. Secure the edges with a fork. Make similar calzones with the remaining dough and stuffing.
Line a baking tray with butter paper and brush with some oil / melted butter. Gently place the prepared calzones.
Lightly brush with the egg wash and bake in a preheated oven at 200 degrees C. for 20-25 minutes or till the top is light golden in colour. Serve with tomato ketchup, mayo or green chutney.